The present invention relates generally to valve assemblies and more particularly to a replaceable liner for a knife gate type valve assembly.
In the mining and other industries, knife gate type valves are used to control the flow of fluids and are typically positioned in the flow line between adjacent ends of fluid flow conduits or pipes. The knife gate valves are characterized by a housing defining a circular passage therethrough aligned with the adjacent fluid flow conduits and an upward extension having a slot therein which slidably receives a slide gate. The slide gate is adapted to be moved between a closed position wherein it blocks the passage through the valve and a retracted open position allowing the flow of fluid through the valve. Typically, knife gate valves liners of a stainless steel material which are relatively long-lasting by being resistant to corrosion and erosion by the fluids flowing through the valve. These liners, however, ultimately wear out depending upon the use of the valve and the type of fluids being conducted through the valve.
Prior to the present invention, when a liner became worn to the point where it no longer served the purpose for which it was intended, the valve would either have to be replaced by a new valve or the stainless steel liner removed by a very expensive process and replaced with a new stainless steel liner. Knife gate valves depending upon their size and intended use can be very expensive and have been relatively large expense factors in the maintenance of certain operations such as in the mining industry.
Accordingly, there has long been a need for a system of maintaining knife gate valves in good working condition in a relatively inexpensive and maintenance free manner. The present invention is intended to satisfy this need.